This sort of damaged is something that happens with cars that are used by disabled people and something that can’t be avoided. This is why Motability are very forgiving of excessive wear and tare to our cars so no need to worry about GCB and all that.
That said as your like most of us and like to keep the cars as if they were our own there are ways to prevent damage to the loading area of the boot.
Just as an example I currently have a scooter hoist in my car, it’s the first car I’ve had with such a hoist and it lifts my scooter clear of any paintwork at the back of the car and two years to date it hasn’t a mark on it.
On my previous cars where I/we had to man handle my scooter into the boot the rear boot sill had loads of scratches, some very deep as it can’t be help but after a few years of my cars suffering this damage and becoming an embarrassment to me I hit on the ideal of using a bit of loose folded carpet in the boot. So with the boot empty awaiting the loading of my scooter we would unfold the upper fold of the carpet leaving half still on the floor of the boot then letting the other half drape down over the back body and paintwork, load the scooter then fold the carpet back over the loaded scooter.
I used a pick nick type carpet at first but when we renewed our living room carpet I had an off cut of that but it does work wonders in protecting the back of the car.